JPH11102665A - Lighting and instrumentation - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an illumination device in which discharge is stable even at the time of dimming. SOLUTION: An inverter circuit 52 is connected to a DC power supply E via a PWM modulator 51 to form a dimming lighting device 53,
It is connected to the rare gas discharge lamp 21 via a lamp current limiting capacitor C1. The rare gas discharge lamp 21 has an inner diameter of 6 mm.
A bulb 23 made of, for example, glass having the following translucency is provided. In the bulb 23, xenon (X
e) Gas is sealed at about 80 torr. A proximate conductor 29 such as an aluminum tape is provided at the outermost curved portion of the bulb 23 and has a width smaller than the diameter of the positive column in the discharge path 25 and is 2 mm or less. By performing PWM control, the range of dimming is widened. Even if the positive column is thinned due to dimming, it is attracted to the proximity conductor 29 to prevent flicker. Valve 23
By forming the proximity conductor 29 at the outermost curved portion of the above, the discharge path in the discharge path 25 can be made the longest, and the luminous efficiency is improved by making the positive column long.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device and an instrument device that stabilize discharge even during dimming.

[0002]

2. Description of the Related Art Conventionally, rare gas discharge lamps, such as xenon lamps, are less suitable for applications such as in-vehicle or office automation equipment because of the lack of absolute light quantity and the inability to perform a wide range of dimming compared to mercury lamps. Not converted.

However, in recent years, mercury-free requirements have been increasing from an environmental point of view, and the temperature characteristics are smaller than those of mercury lamps. The demand for discharge lamps is increasing.

In addition, the diameter of the bulb of the rare gas discharge lamp is reduced to increase the absolute light quantity by increasing the load on the wall of the bulb, and the positive column is prevented from swinging and stabilized.

However, when the tube diameter of the bulb of the rare gas discharge lamp is reduced, the discharge starting voltage increases. As a device for lowering the discharge starting voltage, for example, a configuration described in JP-A-1-304654 is known.
Japanese Patent Application Laid-Open No. 1-304654 discloses a method in which a proximity conductor is provided close to a bulb to facilitate discharge and reduce a discharge starting voltage, and to reduce the width of the proximity conductor. It is also possible to prevent the light from being shielded.

On the other hand, when the rare gas discharge lamp is dimmed and lit, the positive column becomes narrower and the discharge becomes unstable.
A configuration described in Japanese Patent No. 49549 is known. Japanese Patent Application Laid-Open No. 3-149549 discloses a method of increasing the resistance value of a nearby conductor, thereby increasing the effect of attracting a positive column, preventing the positive column from swaying, and stabilizing discharge.

[0007]

However, as described in Japanese Patent Application Laid-Open No. Hei 1-304654, the width of the proximity conductor is simply reduced, or as described in Japanese Patent Application Laid-Open No. 3-149549. Simply increasing the resistance value of the lens would cause the positive column to become narrower when dimming, and in particular, the positive column would become narrower with a smaller bulb diameter, which could cause the positive column to sway and become unstable There is.

In the case where the bulb is curved, the discharge path is relatively long, so that there is a problem that the positive column tends to sway.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an illumination device and an instrument device in which discharge is stable even during dimming.

[0010]

According to a first aspect of the present invention, there is provided a lighting apparatus comprising: a rare gas discharge lamp; a nearby conductor having a width smaller than a diameter of a positive column of the rare gas discharge lamp; It is equipped with a dimmable lighting device that can be lit, and the width of the proximity conductor is smaller than the diameter of the positive column, so even if the dimmable lighting is performed by the dimmable lighting device and the diameter of the positive column becomes smaller, The positive column is reliably attracted to the nearby conductor, and the positive column is prevented from shaking to be stably lit.

According to a second aspect of the present invention, in the lighting apparatus of the first aspect, the rare gas discharge lamp has a bulb, and the bulb is formed to be curved. Even if the discharge path is relatively long,
Prevents the positive column from swaying for stable lighting.

According to a third aspect of the present invention, in the lighting apparatus of the first or second aspect, the bulb has an inner diameter of 6 mm.
In the following description, the proximity conductor has a width of 2 mm or less, securely attracts the positive column to the proximity conductor without applying a voltage to the proximity conductor, prevents the positive column from swinging, and performs stable lighting.

According to a fourth aspect of the present invention, in the lighting apparatus of the first or second aspect, the bulb has an inner diameter of 3 mm.
Hereinafter, the proximity conductor has a width of 1 mm or less, reliably attracts the positive column to the proximity conductor without applying a voltage to the proximity conductor, prevents the positive column from swinging, and stably lights.

According to a fifth aspect of the present invention, there is provided the lighting device according to any one of the second to fourth aspects, wherein the proximity conductor is provided along the outermost periphery of the bulb, and the length of the discharge path is increased to make the positive column. The luminous efficiency is improved by increasing the length.

According to a sixth aspect of the present invention, there is provided the lighting device according to any one of the first to fifth aspects, wherein the dimming lighting device is a PWM control, and the average voltage can be reduced without reducing the instantaneous voltage at the time of ON. In order to change the on-duty by changing the light intensity, dimming is performed in a wide range.

According to a seventh aspect of the present invention, there is provided an instrument device comprising: a panel provided with an instrument; and the lighting device according to any one of the first to sixth aspects, which is disposed on the back side of the panel. Illuminate and display the instrument with more appropriate brightness.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an instrument device according to the present invention.

1 to 8 show a first embodiment, FIG. 1 is a block diagram showing an illumination device, FIG. 2 is a front view of a discharge lamp, FIG. 3 is a front view of a panel, and FIG. 4 is a reflector. 5, FIG. 5 is a sectional view taken along the line AA in FIG. 4, FIG. 6 is an explanatory view for explaining the light reflecting action of the reflector, FIG. 7 is a graph showing the relationship between the lamp current of the discharge lamp and the relative luminance. 8 is a circuit diagram showing an inverter circuit.

3 and 6, reference numeral 1 denotes an instrument panel unit of an automobile as an instrument device. The instrument panel unit 1 has a panel 2, a plurality of instruments 4, and a lighting device 5.

The panel 2 has a transparent or translucent translucent plate made of, for example, acrylic or glass, which is formed to be horizontally long and transmits light. Except for a portion of the display portion 11 which is a light transmitting portion through which light such as scales, numerals, and symbols formed correspondingly is formed, a black light shielding film for shielding light is formed. Also,
The scale of the display unit 11 is arranged in an arc shape, and numbers and symbols are arranged along the scale.

The instrument 4 is an analog type, and the panel 2
Speedometer 4a and tachometer 4b, panel 2
A fuel gauge 4c and a water temperature gauge 4d are provided at both ends of the instrument, and a display unit 11 is formed corresponding to each of the instruments 4. At the approximate center of each instrument 4, an instrument shaft 12 of an instrument body (not shown) arranged behind the panel 2 projects from the back side of the panel 2 to the front side, and each instrument axis 12 rotates along a scale.
13 is attached. The pointer 13 itself is formed of a discharge tube or the like so as to emit light when energized.

The lighting device 5 has a pair of pipes having an inner diameter of 6 mm or less,
It preferably has a rare gas discharge lamp 21 and a reflector 22 of 3 mm or less. As shown in FIG. 2, the rare gas discharge lamp 21 has a light-transmitting bulb 23 made of, for example, glass, and contains xenon (X) as a discharge medium in the bulb 23.
e) A gas is sealed in at about 80 torr, a phosphor layer which is excited and emits light by the ultraviolet radiation of xenon is coated on the inner wall of the bulb 23, and electrodes 24 as electrode means are provided on both ends of the bulb 23.
Is sealed, and one discharge path 25 in which a positive column is formed is formed between both ends of the bulb 23.

The rare gas discharge lamp 21 has a lamp power of 5 W, an outer diameter of about 3 mm, a length of about 500 mm,
The luminance is about 7000 cd / m ^2, and the luminance of the display unit 11 illuminated and displayed by the rare gas discharge lamp 21 is 1500 cd / m ^2.
/ M ² . Further, as shown in FIG. 7 which shows the relationship between the lamp current of the rare gas discharge lamp 21 and the relative luminance, in the xenon lamp which does not use mercury, the light output hardly increases with an increase in the lamp current. Brightness does not change, but the luminous flux is about 1/4
It has become about.

The rare gas discharge lamp 21 illuminates and displays the adjacent meters 4, that is, the speedometer 4a and the fuel meter 4c, or the display unit 11 of the tachometer 4b and the water temperature meter 4d by one lamp. It is formed corresponding to the shape of the display unit 11 of the total 4a and the fuel total 4c, or the tachometer 4b and the water temperature meter 4d. At one end of the rare gas discharge lamp 21, a display section of a speedometer 4a or a tachometer 4b is provided.
An instrument opposing part 26 opposing along 11 is formed in a substantially arc-shaped curved shape, and a display part of a fuel gauge 4c or a water temperature gauge 4d is provided on the other end side.
A meter facing portion 27 facing along 11 is formed in a substantially arc shape and a connecting portion 28 is formed between the two meter facing portions 26 and 27. The directions of curvature of the two meter opposing portions 26 and 27 are opposite to each other. Further, a proximity conductor 29 such as an aluminum tape is provided on the outermost curved portion of the bulb 23. The width of the proximity conductor 29 in the longitudinal direction is determined by the discharge path.
25, smaller than the diameter of the positive column, 2 mm or less, preferably 1 mm
mm or less. As described above, by forming the proximity conductor 29 on the outermost curved portion of the bulb 23, the discharge path in the discharge path 25 can be maximized, and the luminous efficiency can be improved by lengthening the positive column. . Further, by electrically insulating the proximity conductor 29, it is possible to suppress a leakage current that is not related to the light emission luminance and reduce a power loss.

The rare gas discharge lamp 21 shown in FIG. 2 can be used for illumination display of the display unit 11 of the speedometer 4a and the fuel meter 4c. By turning the rare gas discharge lamp 21 upside down, the tachometer 4b and the water temperature meter can be used. It can be used for the illumination display of the display unit 11 of 4d, and the rare gas discharge lamp 21 can be used in common.

As shown in FIGS. 4 and 5, the reflector 22 is formed to have substantially the same outer shape as the panel 2, and a front surface is formed with a bonding surface 31 to be bonded to the back surface of the panel 2. On the surface 31, there is formed a reflection concave portion 32 facing the shape of the display section 11 of the adjacent instrument 4 illuminated and displayed by each rare gas discharge lamp 21, that is, the shape of each rare gas discharge lamp 21.

The reflecting concave portion 32 is provided with an annular reflecting surface portion 35 facing the display portion 11 of the speedometer 4a or the tachometer 4b, ie, the instrument facing portion 26 of the rare gas discharge lamp 21, and a fuel gauge.
4c or the display section 11 of the water temperature gauge 4d, that is, a rare gas discharge lamp
Curved reflective surface section 3 facing along 21 instrument facing section 27
5. It has a linear reflecting surface 35 that connects the annular portion 33 and the curved portion 34 to face each other along the connecting portion 28 of the rare gas discharge lamp 21.

An instrument mounting portion 36 is formed corresponding to the central portion of each instrument 4, that is, in the center of each annular portion 33 of each reflection concave portion 32, and an instrument is provided on the curved center side of each curved portion 34. A mounting part 37 is formed. These instrument mounting parts 36, 37
The instrument body of each instrument 4 is attached to the back side of the instrument, and the instrument shaft 12 is inserted into each instrument mounting portion 36, 37.

As shown in FIG. 6, an opaque translucent resin diffusion plate 41 is provided between the panel 2 and the lighting device 5. Further, in front of the panel 2, for example, a black translucent cover 42 is provided.

The panel 2, the instrument 4, and the lighting device 5
In a state where the meter panel unit is assembled by, for example, the adjacent instruments 4, that is, the speedometer 4a and the fuel meter 4c,
The instrument facing parts 26 and 27 of the rare gas discharge lamp 21 face each other along the display part 11 of the tachometer 4b and the water temperature gauge 4d. Further, the reflection recess 32 of the reflector 22 is a rare gas discharge lamp.
They are opposed along the 21 instrument facing portions 26 and 27. Reflector 22
, The bonding surface 31 on the front surface is bonded and fixed to the back surface of the panel 2 via the diffusion plate 41.

As shown in FIG. 1, an inverter circuit 52 is connected to the DC power supply E via a PWM modulation device 51, and the PWM modulation device 51 and the inverter circuit 52 constitute a dimming lighting device 53. The circuit 52 is connected to the rare gas discharge lamp 21 via a lamp current limiting capacitor C1.

In the inverter circuit 52, as shown in FIG. 8, a DC constant voltage of 12 V is applied between input terminals A and C, and a DC variable voltage of 1 to 5 V is applied between input terminals B and C. You.

A fuse F is connected between the input terminals A and C.
Is connected in parallel with the smoothing capacitor C2, and a parallel resonance circuit of a primary circuit Tr1a of the inverter transformer Tr1 and capacitors C3 and C4 for parallel resonance and a field effect transistor Q1 are connected in parallel with the smoothing capacitor C2. Are connected in series.

A series circuit of an NPN transistor Q2 and a PNP transistor Q3 is connected between both ends of the capacitor C2.
The connection point of Q3 is connected to field-effect transistor Q1 via resistor R1.
The resistor R2 is connected between the gate and the drain of the field effect transistor Q1.

Further, a diode D1 and a Zener diode ZD are provided between the drain and the source of the field effect transistor Q1.
1 and the base of the transistor Q4 via the resistor R3.
Is connected. The collector of the transistor Q4 is connected to the bases of the transistors Q2 and Q3 via the diodes D2 and D3, and the emitter of the transistor Q4 is connected to the input terminal C.

The secondary winding of the inverter transformer Tr1
Tr1b is connected to the output terminals D and G via the lamp current limiting capacitors C1a and C1b of the lamp current limiting capacitors C1.
, And outputs an AC voltage of 2000 V between these output terminals D and G.

On the other hand, input terminals A and C via fuse F
A smoothing capacitor C5 is connected between them, and IC55 and IC56 are connected to the capacitor C5.

A capacitor is provided between the input terminals B and C.
C6, resistors R5, R6, R7, R8, R9 and capacitor C7 are connected. Further, capacitors C8 and C9 and a resistor R10 are connected to the IC 55. Further, the IC 56 includes a capacitor C10, diodes D2 and D3, and resistors R11, R12, and R1.
3, R14, capacitor C11, diode D4 and resistor R1
4 is connected.

Next, the operation of this embodiment will be described.

When a DC power supply voltage is applied between the input terminals A and C, the IC 56 operates. Then, the third terminal is operated at the set constant frequency and on-off duty. Outputs the DC power supply voltage when on, and GN when off
The state is the D potential. When the third terminal of the IC 56 is turned on to output a voltage, the transistor Q2 is turned on via the resistor R14 and the diode D2. Resistance when transistor Q2 turns on
The power supply voltage divided by R1 and the resistor R2 is applied to the gate of the field effect transistor Q1 to turn on the field effect transistor Q1. Also, when the third terminal of the IC 56 is turned off and becomes the GND potential, the voltage stored in the base of the transistor Q2 is extracted to turn off the transistor Q2, and the transistor Q2 is turned off.
Turn on Q3. When the transistor Q3 is turned on, the voltage applied to the gate of the field effect transistor Q1 is pulled out via the resistor R1, and the field effect transistor Q1 is turned off. The turning on and off of the field effect transistor Q1 causes the primary winding Tr of the inverter transformer Tr1 to turn on and off.
The inverter transformer Tr1 is formed by the resonance voltage of the parallel resonance circuit 54 composed of the inductance 1a and the capacitors C3 and C4.
A high-frequency voltage is generated in the primary winding Tr1a, and the secondary winding Tr1b
And applied to the rare gas discharge lamp 21.

The PWM dimming is performed by connecting the terminals 8 and 11 to the power supply GND when the IC 55 is turned on, and repeatedly oscillating at a constant frequency of about 100 to 5000 Hz to be opened when the IC 55 is turned off by controlling the on-duty. Dimming.
Now, when the 8th and 11th terminals of IC55 turn on, the transistor
Q2 turns off and the field effect transistor Q1 turns off. Thus, the off time of the field effect transistor Q1 is controlled by controlling the on time of the 8th and 11th terminals of the IC 55.

When the rare gas discharge lamp 21 is turned on, the direct light of the rare gas discharge lamp 21 and the reflection concave portion of the reflector 22 are formed.
The reflected light reflected by the light 32 passes through the display section 11 of the instrument 4 formed on the panel 2 through the diffusion plate 41, and illuminates and displays the display section 11 of the instrument 4 brightly. At this time, the panel 2 and the lighting device 5
Since the diffusion plate 41 is provided between the display device 11 and the display device 11, unevenness in light of the display unit 11 can be prevented by the light diffusion effect of the diffusion plate 41.

The rare gas discharge lamp 21 has a proximity conductor 29
Is provided, the starting voltage can be reduced, the bulb 23 is made thinner, and the width of the proximity conductor 29 is smaller than the diameter of the positive column. Since the positive column is attracted to the conductor 29,
Even if the diffusion state and the contraction state are repeated in the dimming state in which the positive column becomes narrow, the positive column does not fluctuate, so that it can be stably lit without flicker. Further, since the proximity conductor 29 is formed on the curved outer periphery of the bulb 23, the discharge path of the positive column can be long, and the luminous efficiency can be improved.

Further, the display unit 11 of each of the adjacent instruments 4, that is, the speedometer 4a and the fuel gauge 4c, and the tachometer 4b and the water temperature gauge 4d.
Since the instrument facing portions 26 and 27 of each rare gas discharge lamp 21 face each other, even if the rare gas discharge lamp 21 is a xenon lamp and the luminous flux is low, the display section 11 of each instrument 4 can be sufficiently brightly illuminated. Can be displayed. Moreover, since the display portions 11 of the two instruments 4 can be illuminated and displayed by one rare gas discharge lamp 21,
Even if there are four instruments 4, only two rare gas discharge lamps 21 need to be used, and the assemblability of wiring and the like can be improved.

Further, since the reflector 22 has the reflection concave portion 32 facing the instrument facing portions 26 and 27 of the rare gas discharge lamp 21, the light of the rare gas discharge lamp 21 is concentrated on the display section 11 of the instrument 4. Thus, the display section 11 of the instrument 4 can be illuminated and displayed more brightly.

Further, since the reflector 22 has the instrument mounting portions 36 and 37 adjacent to the reflection concave portion 32, the instrument mounting portions 36 and 37 are provided.
Each instrument 4 can be mounted by utilizing.

Next, a second embodiment will be described with reference to FIG.

The same structure and operation and effect as those of the first embodiment will be described using the same reference numerals.

FIG. 9 is a front view of the discharge lamp. As shown in FIG. 9, the rare gas discharge lamp 21 has the instrument facing part 26 in the opposite direction to the rare gas discharge lamp 21 of the first embodiment. And the adjacent conductors 29 are formed at the outermost peripheral portions, that is, the bending directions of the two meter facing portions 26 and 27 are opposite to each other.

The operation and effect of the rare gas discharge lamp 21 are the same as those of the first embodiment.

Next, a third embodiment will be described with reference to FIGS.

The same structures and functions and effects as those of the above embodiment are denoted by the same reference numerals and their description is omitted.

FIG. 10 is a front view of the discharge lamp, and FIG. 11 is a front view of the reflector. As shown in FIGS.
The rare gas discharge lamp 21 is used to illuminate and display the display units 11 of the four instruments 4.
The two instrument opposing portions 26 are formed respectively, and the instrument opposing portions 27 are formed at both ends, respectively.
26 and 27 are connected by a connection unit 28.

The reflector 22 includes a rare gas discharge lamp 21.
One continuous reflection concave portion 32 is formed in accordance with the shape of (1).

Therefore, since the display portions 11 of the four instruments 4 can be illuminated and displayed by one rare gas discharge lamp 21, the instruments 4
Even if there are four, only one rare gas discharge lamp 21 needs to be used, and the assemblability of wiring and the like can be improved.

In each of the above embodiments, one rare gas discharge lamp 21 is used for two or four instruments 4, but three or five or more instruments 4 can be used. You may.

Next, a fourth embodiment will be described with reference to FIG.

It is to be noted that the same reference numerals are used for the same structures, functions, and effects as those of the above-described embodiments, and description thereof is omitted.

FIG. 12 is a sectional view of the discharge lamp.
As shown in FIG. 2, the rare gas discharge lamp 21 has a bulb 23 having a length of about 500 mm, an outer diameter of about 3 mm, and a wall thickness of about 0.5 m.
m, a material such as Pyrex (trade name) having a softening temperature of about 820 ° C.
m of the phosphor layer is formed on the outer surface of the bulb 23.
Is provided, and xenon (X
e) Gas is charged at a pressure of about 80 torr.
The rare gas discharge lamp 21 has a lamp power of 5 W and a lamp luminance of 7000 cd / m ² (white).

The proximity conductor 29 is made of, for example, aluminum and bonded to the outer surface of the bulb 23 and has a width of about 0.5 mm.
23 is arranged along the pipe axis direction and the valve 23
Are extended to the end side from the positions of the electrodes 24 at both ends of the first electrode. The proximity conductor 29 is connected to the same potential as the one electrode 24 of the bulb 23, is connected to the ground, or is not electrically connected.

A dimming lighting device 53 for PWM dimming the rare gas discharge lamp 21 is provided on the electrodes 24 at both ends of the bulb 23.
Is connected. In this dimming lighting device 53, 30 kHz
The rare gas discharge lamp 21 is turned on at a frequency of
It is configured to dimm at a PWM dimming frequency of z.

Further, with such a rare gas discharge lamp 21,
Prototype only the material of the bulb 23 with soft glass such as soda lime glass used in ordinary lighting lamps,
When a lighting test in which 70% dimming was performed at a lamp current of 6 mA was performed, leakage was confirmed from about 100% after a lapse of several hundred hours, although the probability was about 1%. When the state of the leak was confirmed, 0.5 m
There was a hole of about m, and there was a leak from this hole. It was found that the holes had a very uniform shape and were not due to the impact of discharge, but were created through thermal effects.

That is, when a forced test was performed by increasing the current by three times, discharge occurred first between the electrode 24 and the adjacent conductor 29, and if this continued for a long time, the discharge between the electrode 24 and the adjacent conductor 29 occurred. It was found that the tube wall of the bulb 23 located was heated, and eventually a hole was formed, very locally above the softening temperature of the glass.

Generally, in a discharge lamp filled with xenon gas, when the current value exceeds a certain value, the arc becomes linear, so that such a problem is more likely to occur. Lamps do not have this problem due to the arc spreading.

Therefore, the rare gas discharge lamp 21
Then, the valve 23 is made of a glass material having a softening temperature of 700 ° C. or more,
For example, Pyrex (product name) with a softening temperature of about 820 ° C
The electrode 24 and the adjacent conductor
Even if a discharge occurs between the electrode 29 and the bulb 23 located between the electrode 24 and the adjacent conductor 29, the bulb 23 can be prevented from leaking.

The structure of the rare gas discharge lamp 21 of the fourth embodiment may be applied to the rare gas discharge lamps 21 of the first to third embodiments.

Next, FIGS. 13 to 17 show a fifth embodiment.

The same structures and functions and effects as those of the above-described embodiments are denoted by the same reference numerals and description thereof is omitted.

FIG. 13 is a front view of a discharge lamp, FIG. 14 is a front view of a panel, FIG. 15 is a front view of a reflector, FIG. 16 is a plan view showing a rare gas discharge lamp, and FIG. 17 is a rare gas discharge lamp. It is a front view, as shown in FIGS. 13 to 15, using one rare gas discharge lamp 21 having an inner diameter of 6 mm or less, preferably 3 mm or less, corresponding to each instrument 4. The rare gas discharge lamp 21 corresponding to the display section 11 of the speedometer 4a and the tachometer 4b is bent substantially in a C-shape to form an instrument facing section 26, and the fuel gauge 4c and the water temperature gauge
The rare gas discharge lamp 21 corresponding to the display section 11 of 4d is bent in a semi-annular shape to form an instrument facing section 27.

As shown in FIGS. 16 and 17, the rare gas discharge lamp 21 has a width of 2 mm at the outermost periphery of the bulb 23.
In the following, the proximity conductor 29 of, for example, aluminum tape is provided as a conductive tape or a conductive tape of preferably 1 mm or less, and the same operation and effect as in the above-described case are exerted.

Further, the reflector 22 is formed with a reflection recess 32 which is opposed to the shape of the display section 11 of each instrument 4, that is, the shape of each rare gas discharge lamp 21, corresponding to each instrument 4. I have. A holder 71 for detachably holding an intermediate portion of the bulb 23 of the rare gas discharge lamp 21 is provided in each reflection recess 32. When the rare gas discharge lamp 21 is used, the holder 71 may be an electric connection means for electrically connecting to the proximity conductor 29. When the proximity conductor 29 is to be insulated, the holder 71 is made of an electric insulator.

Then, the rare gas discharge lamp 21 is
Since the positive column inside generates the discharge in a stable state, the flicker of the brightness of the instrument 4 is small, and the stable brightness can be secured.

The shape of the rare gas discharge lamp 21 only needs to correspond to the shape of the display unit 11 of the instrument 4.

When the illuminance can be switched between day and night and the illuminance can be arbitrarily adjusted, even when the illuminance is reduced, the flicker of the brightness of the instrument 4 can be reduced and stabilized by the proximity conductor 29 even when the illuminance is reduced. Can be.

Here, the proximity conductor 29 of the rare gas discharge lamp 21
The experimental results of the relationship between the width and the flicker will be described.

First, xenon 100% and 70 Torr,
With respect to the discharge lamp 21 having the bulb 23 having an inner diameter of 3 mm and a length of 270 mm, when observing flickering on the adjacent conductor 29 having a width of 3 mm, 2 mm and 1 mm, as shown in Table 1, when the on-duty is 100%, No flicker can be observed in any case, but when the width is 3 mm, flicker is observed when the on-duty becomes 40% or less, and when the width is 2 mm, flicker is observed when the on-duty becomes 90% or less, and when the width is 1 mm. No flicker is observed even when the on-duty is 2%.

[0077]

[Table 1] In addition, xenon 100% is 70 Torr, inner diameter is 2 mm,
Observation of the flicker of the adjacent conductors 29 having a width of 3 mm, 2 mm, and 1 mm for the discharge lamp 21 having the bulb 23 having a length of 270 mm, as shown in Table 2, when the on-duty is 100%, all flicker. Cannot be observed, but when the width is 3 mm, the on-duty is 1
When the width is 2% or less, flicker is observed. When the on-duty is 10% or less, flicker is observed. When the on-duty is 2%, no flicker is observed.

[0078]

[Table 2] From these results, it can be understood that the inner diameter of the bulb 23 is small and the flutter is less likely to occur, and the narrow width of the adjacent conductor 29 is less likely to be observed.

Next, another embodiment of the rare gas discharge lamp 21 will be described with reference to FIGS.

FIG. 18 is a plan view showing a rare gas discharge lamp.
FIG. 19 is a front view showing a rare gas discharge lamp. The rare gas discharge lamp 21 shown in FIGS.
In the rare gas discharge lamp 21 shown in FIGS. 6 and 17, a transparent conductive proximity conductor 29 is provided in the instrument facing portion 26 of the rare gas discharge lamp 21.

When the transparent proximity conductor 29 is formed in the instrument facing portion 26 in this way, as shown in FIG. 20, the luminance distribution on the proximity conductor side is increased, so that the instrument 4 can be more efficiently illuminated.

Further, another embodiment of the rare gas discharge lamp 21 will be described with reference to FIGS. 21 and 22.

FIG. 21 is a plan view showing a rare gas discharge lamp.
FIG. 22 is a front view showing a rare gas discharge lamp. The rare gas discharge lamp 21 shown in FIGS.
In the rare gas discharge lamp 21 shown in FIG. 6 and FIG. 17, a transparent conductor 29 having a transparent conductivity is provided in the meter facing portion 26 in the outermost portion near the both ends of the rare gas discharge lamp 21 and in the middle portion.

Also in this case, since the luminance distribution on the side of the proximity conductor 29 is increased, the instrument 4 can be illuminated more efficiently.

In any of the embodiments, the same effect can be obtained even if the proximity conductor 29 has a transparent conductivity.

[0086]

According to the illumination device of the first aspect, since the width of the adjacent conductor is smaller than the diameter of the positive column, the dimming operation is performed by the dimming lighting device so that the diameter of the positive column becomes smaller. Even so, the positive column can be reliably attracted to the nearby conductor, and the positive column can be prevented from shaking to achieve stable lighting.

According to the illumination device of the second aspect, in addition to the illumination device of the first aspect, since the bulb of the rare gas discharge lamp is curved, the discharge path is relatively formed by the bulb being curved. Even if it becomes longer, the positive column can be prevented from shaking and stable lighting can be achieved.

According to the lighting device of the third aspect, in addition to the lighting device of the first or second aspect, the bulb has an inner diameter of 6 m.
m or less, and the width of the proximity conductor is 2 mm or less, so that the positive column can be reliably attracted to the proximity conductor without applying a voltage to the proximity conductor, and the positive column can be prevented from swinging and can be stably lit.

According to the lighting device of the fourth aspect, in addition to the lighting device of the first or second aspect, the bulb has an inner diameter of 3 m.
m or less, and the width of the proximity conductor is 1 mm or less, so that the positive column can be securely attracted to the proximity conductor without applying a voltage to the proximity conductor, and the positive column can be prevented from shaking and can be stably lit.

According to the illuminating device of the fifth aspect, in addition to the illuminating device of any of the second to fourth aspects, the proximity conductor is provided along the outermost periphery of the bulb, so that the discharge path is lengthened to increase the sunlight. Luminous efficiency can be improved by lengthening the columns.

According to the lighting device of the sixth aspect, in addition to the lighting device of any one of the first to fifth aspects, the dimming lighting device is PWM controlled, so that the instantaneous voltage at the time of ON is kept constant. Dimming can be performed in a wide range because the on-duty is changed.

According to the instrument device of the present invention, since the illumination device according to any one of claims 1 to 6 is provided on the back surface side of the panel on which the instrument is provided, more appropriate light control is achieved. The meter can be illuminated and displayed with brightness.

[Brief description of the drawings]

FIG. 1 is a block diagram of a lighting device according to a first embodiment of the present invention.

FIG. 2 is a front view of the discharge lamp.

FIG. 3 is a front view of the panel.

FIG. 4 is a front view of the reflector.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is an explanatory diagram illustrating a light reflecting action of the reflector.

FIG. 7 is a graph showing a relationship between a lamp current and a relative luminance of the discharge lamp.

FIG. 8 is a circuit diagram showing the inverter circuit according to the first embodiment;

FIG. 9 is a front view of a discharge lamp according to the second embodiment.

FIG. 10 is a front view of a discharge lamp according to the third embodiment.

FIG. 11 is a front view of the reflector.

FIG. 12 is a sectional view of a discharge lamp according to the fourth embodiment.

FIG. 13 is a sectional view of a discharge lamp showing a fifth embodiment of the present invention.

FIG. 14 is a front view of the panel.

FIG. 15 is a front view of the reflector.

FIG. 16 is a plan view showing a rare gas discharge lamp according to another embodiment of the present invention.

FIG. 17 is a front view showing the rare gas discharge lamp.

FIG. 18 is a plan view showing a rare gas discharge lamp according to another embodiment of the present invention.

FIG. 19 is a front view showing the rare gas discharge lamp.

FIG. 20 is an explanatory diagram showing a luminance distribution according to the embodiment.

FIG. 21 is a plan view showing a rare gas discharge lamp showing still another embodiment of the present invention.

FIG. 22 is a front view showing the rare gas discharge lamp.

[Description of Signs] 1 Meter panel unit as instrument device 5 Lighting device 21 Rare gas discharge lamp 23 Bulb 29 Proximity conductor 53 Dimmable lighting device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kunio Yuasa, Inventor 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Lighting & Technology Corporation (72) Inventor Kiyoshi Nishimura 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Lighting & Technology Corporation

Claims (7)

[Claims] A rare gas discharge lamp; a proximity conductor having a width smaller than a diameter of a positive column of the rare gas discharge lamp; and a dimming lighting device capable of dimming and lighting the rare gas discharge lamp. A lighting device characterized by the above-mentioned. 2. The lighting device according to claim 1, wherein the rare gas discharge lamp has a bulb, and the bulb is curved. 3. The lighting device according to claim 1, wherein the bulb has an inner diameter of 6 mm or less, and the adjacent conductor has a width of 2 mm or less. 4. The lighting device according to claim 1, wherein the bulb has an inner diameter of 3 mm or less, and the adjacent conductor has a width of 1 mm or less. 5. The lighting device according to claim 2, wherein the proximity conductor is provided along an outermost periphery of the bulb. 6. The lighting device according to claim 1, wherein the dimming lighting device is a PWM control. 7. An instrument device comprising: a panel provided with an instrument; and the lighting device according to claim 1, which is disposed on a back side of the panel.